Approved Document H - Drainage and waste disposal

This part covers details of foul water drainage, both above and below ground, pipe sizes, protection of pipes, manholes and inspection chambers, rodding access, testing, etc. Waste water treatment systems, cesspools, rainwater drainage, building over public sewers, separate systems of drainage and storage provisions for rubbish and recycled waste.

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The requirements in this edition of Approved Document H are as follows:

H1 - Foul water drainage
(1) An adequate system of drainage shall be provided to carry foul water from appliances within the building to one of the following, listed in order of priority:
(a) a public sewer; or, where that is not reasonably practicable,
(b) a private sewer communicating with a public sewer; or, where that is not reasonably practicable,
(c) either a septic tank which has an appropriate form of secondary treatment or another wastewater treatment system; or, where that is not reasonably practicable,
(d) a cesspool.
(2) In this Part 'foul water' means waste water which comprises or includes:
(a) waste from a sanitary convenience, bidet or appliance used for washing receptacles for foul waste; or
(b) water which has been used for food preparation, cooking or washing.

Limits on application
Requirement H1 does not apply to the diversion of water which has been used for personal washing or for the washing of clothes, linen or other articles to collection systems for re-use.

H2 - Wastewater treatment systems and cesspools
(1) Any septic tank and its form of secondary treatment, other wastewater treatment system or cesspool, shall be so sited and constructed that:
(a) it is not prejudicial to the health of any person;
(b) it will not contaminate any watercourse, underground water or water supply;
(c) there are adequate means of access for emptying and maintenance; and
(d) where relevant, it will function to a sufficient standard for the protection of health in the event of a power failure.
(2) Any septic tank, holding tank which is part of a wastewater treatment system or cesspool shall be :
(a) of adequate capacity;
(b) so constructed that it is impermeable to liquids; and
(c) adequately ventilated.
(3) Where a foul water drainage system from a building discharges to a septic tank, wastewater treatment system or cesspool, a durable notice shall be affixed in a suitable place in the building containing information on any continuing maintenance required to avoid risks to health.

Limits on application
None

H3 - Rainwater drainage
(1) Adequate provision shall be made for rainwater to be carried from the roof of the building.
(2) Paved areas around the building shall be so constructed as to be adequately drained.
(3) Rainwater from a system provided pursuant to sub-paragraphs (1) or (2) shall discharge to one of the following, listed in order of priority:
(a) an adequate soakaway or some other adequate infiltration system; or, where that is not reasonably practicable,
(b) a watercourse; or, where that is not reasonably practicable,
(c) a sewer.

Limits on applicationRequirement H3(2) applies only to paved areas:
(a) which provide access to the building pursuant to requirement M1 (access and use of buildings other than dwellings), or requirement M2 (access to extensions to buildings other than dwellings), or requirement M4(1), (2) or (3) (access to and use of dwellings);
(b) which provide access to or from a place of storage pursuant to paragraph H6(2) (solid waste storage); or
(c) in any passage giving access to the building, where this is intended to be used in common by the occupiers of one or more other buildings.
Requirement H3(3) does not apply to the gathering of rainwater for re-use.

H4 - Building over sewers
(1) The erection or extension of a building or work involving the underpinning of a building shall be carried out in a way that is not detrimental to the building or building extension or to the continued maintenance of the drain, sewer or disposal main.
(2) In this paragraph 'disposal main' means any pipe, tunnel or conduit used for the conveyance of effluent to or from a sewage disposal works, which is not a public sewer.
(3) In this paragraph and paragraph H5 'map of sewers' means any records kept by a sewerage undertaker under section 199 of the Water Industry Act 1991. 1991 c. 56; Section 199 was amended by Section 97 of the Water Act 2003 (c. 37).

Limits on applicationRequirement H4 applies only to work carried out:
(a) over a drain, sewer or disposal main which is shown on any map of sewers; or
(b) on any site or in such a manner as may result in interference with the use of, or obstruction of the access of any person to, any drain, sewer or disposal main which is shown on any map of sewers.

H5 - Separate systems of drainage
Any system for discharging water to a sewer which is provided pursuant to paragraph H3 shall be separate from that provided for the conveyance of foul water from the building.

Limits on applicationRequirement H5 applies only to a system provided in connection with the erection or extension of a building where it is reasonably practicable for the system to discharge directly or indirectly to a sewer for the separate conveyance of surface water which is:
(a) shown on a map of sewers; or
(b) under construction either by the sewerage undertaker or by some other person (where the sewer is the subject of an agreement to make a declaration of vesting pursuant to section 104 of the Water Industry Act 1991). Section 104 was amended by Section 96 of the Schedule 9 to the Water Act 2003 and is prospectively amended by Section 42 of the Flood and Water management Act 2010 (c. 29).

H6 - Solid waste storage
(1) Adequate provision shall be made for storage of solid waste.
(2) Adequate means of access shall be provided:
(a) for people in the building to the place of storage; and
(b) from the place of storage to a collection point (where one has been specified by the waste collection authority under section 46 (household waste) or section 47 (commercial waste) of the Environmental Protection Act 1990 (*) or to a street (where no collection point has been specified).
(*) 1990 c. 43; Section 46 was amended by Section 19 of the London Local Authorities Act 2007 (2007 c. ii) and Section 47 was amended by Section 21 of that Act. Section 46 was also amended by Section 76 and Schedule 5 to the Climate Change Act 2008 (c. 28).

Quick links to other Approved Documents

The regulations cover all aspects of construction and are constantly reviewed. The guidance documents referred to as 'Approved Documents' contain practical ways and explanations of how to comply with the functional requirements of the Building Regulations.